The basic rule for platform, SPI, and (new style) I2C drivers is just
to make sure that modprobing the driver name works. In this case, all
the relevant drivers are platform drivers, and this patch either

(a) Changes the driver name, if no in-tree code would break;
this is simpler and thus preferable in the long term.

(b) Adds MODULE_ALIAS directives, when in-tree platforms declare
devices using the current driver name; less desirable.

Most systems will link SPI controller drivers statically, but
there's no point in being needlessly broken.